How does Robert Creeley use imagery in Fading Light?

Creeley begins the poem with a reference to a light that seems to shift as it fades. This image is followed by musing about the world, and an elliptical question, "is it as / ever . . ." Then halfway through the poem Creeley introduces imagery of "sitting "patient" (not patiently) followed by the accelerating phrases and images of a sled plunging down "beyond sight."